Module test socket for over the air testing of radio frequency integrated circuits

Abstract

A test system includes a test socket assembly for capturing low energy electromagnetic emissions from radio frequency (RF) integrated circuits (ICs). The test socket assembly is structured to direct electromagnetic radiation from the device under test (DUT) to a socket port coupled to one end of a waveguide for transmission to a tester. The combination of the materials comprising the socket assembly is selected to more efficiently couple electromagnetic emissions from the DUT into the waveguide. For example, a reflective plane with an adjustable position may be located below the DUT in order to increase coupling of electromagnetic radiation from the DUT into the waveguide.

What is claimed is: 
     
       1. A test system for testing an integrated circuit Device-Under-Test (DUT), the DUT including a radiative element that emits close-proximity radio frequency (RF) electromagnetic radiation, the test system comprising:
 a test socket that holds the DUT during testing; 
 an interface board electrically connected between tester instrumentation and electrical contacts of the DUT during testing; 
 a waveguide integrated into the test socket, the waveguide having a first end positioned to receive the RF electromagnetic radiation side emitted by the DUT during testing, the waveguide relaying the RF electromagnetic radiation to the tester instrumentation; 
 a reflective plane positioned below the DUT to reflect the RF electromagnetic radiation, the reflective plane increasing coupling of the RF electromagnetic radiation from the DUT into the waveguide; and 
 a position adjustment mechanism to adjust a position of the reflective plane relative to a position of the DUT. 
 
     
     
       2. The test system of  claim 1 , wherein the reflective plane is positioned 5-10 mil below the DUT. 
     
     
       3. The test system of  claim 1 , wherein the position adjustment mechanism is configured to tilt the reflective plane relative to the DUT. 
     
     
       4. The test system of  claim 1 , wherein the position adjustment mechanism is configured to change a spacing between the reflective plane and a bottom surface of the DUT. 
     
     
       5. The test system of  claim 1 , wherein the position adjustment mechanism is configured to translate the reflective plane relative to the DUT, thereby changing a separation between the reflective plane and the first end of the waveguide. 
     
     
       6. The test system of  claim 1 , wherein adjusting the position of the reflective plane changes an angle of propagation of the electromagnetic radiation emitted by the DUT. 
     
     
       7. The test system of  claim 1 , wherein the radiative element is separated from the first end of the waveguide by an air gap. 
     
     
       8. The test system of  claim 1 , wherein the air gap is less than 2 mm. 
     
     
       9. The test system of  claim 1 , wherein the DUT when able to pass a testing routine of the tester instrumentation has sufficient radiative power to enable reliable reception by a receiver radiative element placed within an envelope of the RF electromagnetic radiation, but insufficient radiative power to enable reliable reception by a receiver radiative element placed outside the envelope. 
     
     
       10. The test system of  claim 9 , wherein the envelope is less than 2 centimeters in its longest dimension. 
     
     
       11. The test system of  claim 9 , wherein the radiative element has a longest dimension that is less than 1 centimeter. 
     
     
       12. The test system of  claim 1 , wherein the RF electromagnetic radiation side emitted from the DUT is EHF radiation having a frequency between 30 GHz and 300 GHz. 
     
     
       13. The test system of  claim 1 , wherein the test socket comprises:
 a socket base with a cavity, the cavity receiving the DUT during testing; and 
 a socket plunger situated above the socket base, the socket plunger pressing the DUT into the cavity during testing. 
 
     
     
       14. The test system of  claim 13 , wherein the tester instrumentation controls the socket plunger to automatically and sequentially obtain and then press DUTs into the cavity for testing. 
     
     
       15. The test system of  claim 13 , wherein the socket plunger includes a conductive sheet that increases coupling of the RF electromagnetic radiation from the DUT into the waveguide. 
     
     
       16. The test system of  claim 13 , wherein the socket plunger is composed of a material with a permittivity (Er) of at least 5. 
     
     
       17. The test system of  claim 13 , further comprising a socket lid, the socket plunger extending through the socket lid into the cavity, the socket lid including a conductive sheet. 
     
     
       18. The test system of  claim 13 , wherein a portion of the cavity in proximity to the first end of the waveguide is composed of a material with a permittivity (Er) of at least 5. 
     
     
       19. The test system of  claim 1 , wherein the DUT includes a plurality of radiative elements that each side emits close-proximity RF electromagnetic radiation, the test system comprising a plurality of waveguides integrated into the test socket, each waveguide having a first end positioned to receive RF electromagnetic radiation side emitted by a different radiative element of the DUT during testing, each waveguide relaying the received RF electromagnetic radiation to the tester instrumentation. 
     
     
       20. The test system of  claim 19 , wherein the radiative elements are separated by not more than 20 mm. 
     
     
       21. The test system of  claim 19 , wherein the radiative elements are separated by not more than 10 mm. 
     
     
       22. The test system of  claim 19 , wherein the test system is configured to measure cross talk between the radiative elements. 
     
     
       23. The test system of  claim 19 , wherein each radiative element can be tested independently from the other radiative elements. 
     
     
       24. The test system of  claim 1 , wherein the DUT can be tested without use of a radiation chamber. 
     
     
       25. The test system of  claim 1 , wherein the DUT can be tested without use of a horn antenna. 
     
     
       26. The test system of  claim 1 , wherein the waveguide is hollow. 
     
     
       27. The test system of  claim 1 , wherein the waveguide is a dielectric waveguide. 
     
     
       28. The test system of  claim 1 , wherein the waveguide is flexible. 
     
     
       29. The test system of  claim 1 , wherein the tester instrumentation is configured to measure radiated power. 
     
     
       30. The test system of  claim 1 , wherein the tester instrumentation is configured to measure receiver sensitivity. 
     
     
       31. The test system of  claim 1 , wherein the tester instrumentation is configured to measure jitter. 
     
     
       32. The test system of  claim 1 , wherein the position adjustment mechanism is electronic and/or mechanical.